Answer:
[tex]\begin{cases}x=-5\\y=-7\end[/tex]
Step-by-step explanation:
[tex]\begin{cases}-x-2y=19\left(1)\right\\-x-y=12\left(2)\right\end[/tex]
(2)-(1)
[tex]y=-7[/tex]
Sub into (2)
[tex]-x+7=12\\x=-5[/tex]
Solutions:
[tex]\begin{cases}x=-5\\y=-7\end[/tex]